A gas cut-off device of this type has hitherto been mentioned in related art documents as a configuration, like that described in connection with Patent Document 1.
FIG. 5 shows a related art flow rate measurement device described in connection with Patent Document 1. As shown in FIG. 5, a rate of gas flow in a gas flow channel 102 is measured at a given time interval, and an arithmetic operation portion 108 computes a difference value of the measured flow rate at regular time intervals. By reference to a flow rate classification table 110a assigned codes that represent classification of a plurality of difference values made by the magnitude of difference values, a difference conversion portion 112 converts a computed difference value into a code. Further, a code sequence generation portion 114 is configured so as to generate a measurement code sequence from a set of codes generated at regular time intervals. An appliance identification portion 116 is configured so as to compare the measurement code sequence with a unique code sequence of each gas appliance, thereby judging a gas appliance that uses a gas.